The present invention relates to an unpacking apparatus for packaged sheets, the apparatus feeding the sheets loaded in bulk in a sheet loading unit onto a transfer board.
This type of conventional unpackaging apparatus for packaged sheets is disclosed in Japanese Patent Laid-Open Publication No. 208449/1988. The apparatus is constructed as follows. The uppermost packaging sheet among the multistage-loaded packaging sheets is moved forwards by a press shift member. With this forward movement, the right and left side faces of the packaging sheet are automatically cut off. The front face of the packaging sheet is cut off just when the forward movement stops. Thereafter, the sheets are pulled out of the packaging sheet which has been unpackaged up and down. The empty packaging sheet is adsorbed by suckers. With a retreat of the press shift member, the empty packaging sheet is fed back above the loaded sheets and then discharged by a discharge belt.
The prior art method disclosed in the foregoing publication presents the following defects. The empty packaging sheet is fed back above the loaded sheets and thereafter discharged. Hence, a feedback stroke from an unpackaging position of the packaging sheet to a discharge position is long. A time loss becomes large, correspondingly. This results in a drop in processing efficiency.